Many filter cartridges are designed to be expendable and fit into a reusable housing 1. The housing 1, typically made of stainless steel or plastic, generally contains a head 2 and a bowl 4 as shown in FIG. 1 and a disposable filter cartridge 6 inside the bowl 4 with a neck or port 8 of the cartridge 6 liquid tightly sealed to a port 10 of the head 2. The head 2 and bowl 4 are capable of being removably mated to each other, generally through the use of corresponding male and female threads 12 and 14 (as shown in FIG. 1) although other means such as snap fittings, bayonet fittings and the like can and have been used. The head 2 of the housing 1 contains a second port 16. One port of the head 2, either 10 or 16, depending on the flow configuration of the system is the inlet for fluid (gas or liquid) into the housing and filter and the other port 16 or 10 respectively, becomes the outlet. Traditionally fluid enters such a housing through port 16, then through the filter to the filter port 8 and then out through the head port 10. A drain plug 5 is generally contained in the bottom of the bowl to allow for draining of the bowl if necessary.
Traditionally, to assemble the filter system as shown in FIG. 1, one liquid tightly seals the port 8 of the cartridge 6 into the port 10 of the head 2 via the O-rings 9 secured to the outer surface 11 of the port 8, then one places the bowl 4 under the cartridge 6 raising it up until the head 2 and bowl 4 meet and then securing the head 2 and bowl 4 together. The O-rings form a friction fit between the ports 8, 10 providing a liquid tight seal between the ports 8, 10.
Problems exist however when the housing 1 is located in a position such that the bowl 4 has insufficient room to be placed under the cartridge 6 that has already been secured to the head 2. Such circumstances exist when the housing is adjacent to the floor or another component of the filtration system. In these instances, one generally places the cartridge 6 in the bowl 2, aligns the bowl 2 and cartridge 6 under the head 2, drops the bowl 4 down to the farthest extent possible and then seizes the cartridge 6 to seal it into the head 2. Often the seal between the port 8 of the cartridge and the port 10 of the head 2 is less than adequate. Several new housing designs have been offered to secure the cartridge within the housing before and after assembly, see U.S. Pat. No. 6,533,933 B1, to overcome this issue. In this design, either the cartridge and bowl are specifically redesigned to provide the required mating devices with in them (such as lugs on the cartridge and slots in the bowl inner surface into which the lugs fit) or at least the bowl is modified to accept a lockable fitting that is attached to an existing cartridge.
However, thousands of housings still exist that have not been replaced with the new bowl/cartridge design. The present invention provides a device for ensuring that the port 8 of the cartridge is aligned and suitably sealed into the port 10 of the head 2 without the need to permanently replace or modify the cartridge and in most embodiments the housing as well.